Hitachi Microscope & Magnifier S-4800 Manual De Usuario

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3.1.4    Use of Anti-Contamination Trap   
 
For image observation at high magnifications or low accelerating voltages, the use of the Anti-
contamination trap is recommended to prevent specimen contamination by hydrocarbon build-up. 
The traps need to be filled with liquid nitrogen. 
 
The Anti-contamination trap is a plate above the specimen that adsorbs 
gas around the specimen. The capacity of the liquid nitrogen dewar is 
about 0.9 liters and is usable for about 5 hours at an ambient 
temperature of 24°C. For initial filling, about 1.3 liters of liquid nitrogen is 
required. 
 
 
 
 
 
 
 
 
CAUTION
 
 
Before using liquid nitrogen, be sure to put on leather gloves and eye guard glasses. If liquid 
nitrogen splashes on your skin, you may suffer frostbite. In addition, the room should be 
ventilated to prevent oxygen depletion.
 
CAUTION
 
 
Never introduce air into the specimen chamber while the anti-contamination trap is filled with 
liquid nitrogen. The anti-contamination trap will frost up and the vacuum will deteriorate. 
Before introducing air into the specimen chamber, wait for a few hours after the liquid 
nitrogen dewer has completely emptied. The air introduction valve does not have a protection 
link with the cold trap.
 
Injection funnel
Dewar vessel
B980022